what has to be done to fit a 400ex motor in a 300ex

[MX wannabe]

i want to put a 400 ex motor in my 300ex i but i heard that i would have to cut the frame and i dont really want to do that. i know that i will need a longer swingarm for the power to not flip me over all the time... thanks

[bwamos]

350x conversion will be much easier. Do some engine work with the extra cash and you'll be of to the races. ;)

[MX wannabe]

what do you mean 350x conversion??? do you just mean do the mods to my motor to boost it to a 350?? like cam, piston, valves, exhaust, and bore or do you mean another motor?
thanks

[400exrider707]

Originally posted by MX wannabe
what do you mean 350x conversion??? do you just mean do the mods to my motor to boost it to a 350?? like cam, piston, valves, exhaust, and bore or do you mean another motor?
thanks

He means swap in the motor from an ATC 350x. Much easier and a million people have already done it. You could pick a 350x engine up cheaper than a 400ex one as well.

[MX wannabe]

ok thanks a lot guys

[wilkin250r]

There is a company called Powroll that actually sells a conversion kit. A few spacers, a little grinding on the motor, NO FRAME MODIFICATIONS, and a custom exhaust, and you're on your way.

[400exrider707]

Originally posted by wilkin250r
There is a company called Powroll that actually sells a conversion kit. A few spacers, a little grinding on the motor, NO FRAME MODIFICATIONS, and a custom exhaust, and you're on your way. is that for the 350x motor or the 400ex motor?

[ZeroLogic]

350x

[ltl666devil]

its very easy to do. heres what it looks like in a 250x.(the same as a 300ex)

[wilkin250r]

Probably in the next few weeks, I'm going to be selling a 350X motor for anybody interested in doing this conversion.

I'm only looking to sell it to somebody knowledgable, however, because I'm not exactly sure what shape the internals are in.